add IPV6_RECVDSTPORT socket option, which enables us to get original

(= before divert) destination port of a UDP packet.  The way to use
this option is same as IP_RECVDSTPORT.

from UMEZAWA Takeshi
tweaks from jmc; ok henning bluhm

5 files changed, 40 insertions, 7 deletions

diff --git a/share/man/man4/ip6.4 b/share/man/man4/ip6.4
index dc54d77f0f8..e704a96de4a 100644
--- a/share/man/man4/ip6.4
+++ b/share/man/man4/ip6.4
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ip6.4,v 1.26 2012/06/20 07:37:01 guenther Exp $
+.\"	$OpenBSD: ip6.4,v 1.27 2012/09/17 20:01:26 yasuoka Exp $
 .\"
 .\" Copyright (c) 1983, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -26,7 +26,7 @@
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
-.Dd $Mdocdate: June 20 2012 $
+.Dd $Mdocdate: September 17 2012 $
 .Dt IP6 4
 .Os
 .Sh NAME
@@ -421,6 +421,17 @@ Get or set the ESP encapsulation level.
 Get or set the
 .Xr ipcomp 4
 level.
+.It Dv IPV6_RECVDSTPORT Fa "int *"
+Get or set the status of whether the destination port for a UDP datagram
+will be provided as ancillary data along with the payload in subsequent 
+.Xr recvmsg 2
+calls.
+The information is stored as a single value of type
+.Vt u_int16_t
+in network byte order.
+.Pp
+Turning this option on will result in this socket getting cmsg data of
+type IPV6_RECVDSTPORT.
 .El
 .Pp
 The
diff --git a/sys/netinet/in_pcb.h b/sys/netinet/in_pcb.h
index 9d4f0d96c91..0ec3cdc01ec 100644
--- a/sys/netinet/in_pcb.h
+++ b/sys/netinet/in_pcb.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in_pcb.h,v 1.72 2012/07/16 18:05:36 markus Exp $	*/
+/*	$OpenBSD: in_pcb.h,v 1.73 2012/09/17 20:01:26 yasuoka Exp $	*/
 /*	$NetBSD: in_pcb.h,v 1.14 1996/02/13 23:42:00 christos Exp $	*/
 
 /*
@@ -196,6 +196,7 @@ struct inpcbtable {
  */
 #define IN6P_HIGHPORT		INP_HIGHPORT	/* user wants "high" port */
 #define IN6P_LOWPORT		INP_LOWPORT	/* user wants "low" port */
+#define IN6P_RECVDSTPORT	INP_RECVDSTPORT	/* receive IP dst addr before rdr */
 #define IN6P_PKTINFO		0x010000 /* receive IP6 dst and I/F */
 #define IN6P_HOPLIMIT		0x020000 /* receive hoplimit */
 #define IN6P_HOPOPTS		0x040000 /* receive hop-by-hop options */
@@ -215,7 +216,7 @@ struct inpcbtable {
 #define IN6P_CONTROLOPTS	(IN6P_PKTINFO|IN6P_HOPLIMIT|IN6P_HOPOPTS|\
 				 IN6P_DSTOPTS|IN6P_RTHDR|IN6P_RTHDRDSTOPTS|\
 				 IN6P_TCLASS|IN6P_AUTOFLOWLABEL|IN6P_RFC2292|\
-				 IN6P_MTU)
+				 IN6P_MTU|IN6P_RECVDSTPORT)
 #endif
 
 #define	INPLOOKUP_WILDCARD	1
diff --git a/sys/netinet/udp_usrreq.c b/sys/netinet/udp_usrreq.c
index 5a8d8e596e4..48700af5473 100644
--- a/sys/netinet/udp_usrreq.c
+++ b/sys/netinet/udp_usrreq.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: udp_usrreq.c,v 1.149 2012/07/17 03:18:57 yasuoka Exp $	*/
+/*	$OpenBSD: udp_usrreq.c,v 1.150 2012/09/17 20:01:26 yasuoka Exp $	*/
 /*	$NetBSD: udp_usrreq.c,v 1.28 1996/03/16 23:54:03 christos Exp $	*/
 
 /*
@@ -688,6 +688,16 @@ udp_input(struct mbuf *m, ...)
 	if (ip && (inp->inp_flags & INP_CONTROLOPTS ||
 	    inp->inp_socket->so_options & SO_TIMESTAMP))
 		ip_savecontrol(inp, &opts, ip, m);
+#ifdef INET6
+	if (ip6 && (inp->inp_flags & IN6P_RECVDSTPORT)) {
+		struct mbuf **mp = &opts;
+
+		while (*mp)
+			mp = &(*mp)->m_next;
+		*mp = sbcreatecontrol((caddr_t)&uh->uh_dport, sizeof(u_int16_t),
+		    IPV6_RECVDSTPORT, IPPROTO_IPV6);
+	}
+#endif /* INET6 */
 	if (ip && (inp->inp_flags & INP_RECVDSTPORT)) {
 		struct mbuf **mp = &opts;
 
diff --git a/sys/netinet6/in6.h b/sys/netinet6/in6.h
index 70a5f0858c6..9bbec7df68d 100644
--- a/sys/netinet6/in6.h
+++ b/sys/netinet6/in6.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in6.h,v 1.58 2012/09/15 00:47:08 guenther Exp $	*/
+/*	$OpenBSD: in6.h,v 1.59 2012/09/17 20:01:26 yasuoka Exp $	*/
 /*	$KAME: in6.h,v 1.83 2001/03/29 02:55:07 jinmei Exp $	*/
 
 /*
@@ -451,6 +451,8 @@ struct route_in6 {
 #define IPV6_DONTFRAG		62   /* bool; disable IPv6 fragmentation */
 #define IPV6_PIPEX		63   /* bool; using PIPEX */
 
+#define IPV6_RECVDSTPORT	64   /* bool; receive IP dst port w/dgram */
+
 #define IPV6_RTABLE		0x1021	/* int; routing table, see SO_RTABLE */
 
 /* to define items, should talk with KAME guys first, for *BSD compatibility */
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index 07aedeed4d2..05126b62c7f 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip6_output.c,v 1.125 2012/07/16 18:05:36 markus Exp $	*/
+/*	$OpenBSD: ip6_output.c,v 1.126 2012/09/17 20:01:26 yasuoka Exp $	*/
 /*	$KAME: ip6_output.c,v 1.172 2001/03/25 09:55:56 itojun Exp $	*/
 
 /*
@@ -1356,6 +1356,7 @@ ip6_ctloutput(int op, struct socket *so, int level, int optname,
 			case IPV6_RECVTCLASS:
 			case IPV6_V6ONLY:
 			case IPV6_AUTOFLOWLABEL:
+			case IPV6_RECVDSTPORT:
 				if (m == NULL || m->m_len != sizeof(int)) {
 					error = EINVAL;
 					break;
@@ -1504,6 +1505,9 @@ do { \
 					OPTSET(IN6P_AUTOFLOWLABEL);
 					break;
 
+				case IPV6_RECVDSTPORT:
+					OPTSET(IN6P_RECVDSTPORT);
+					break;
 				}
 				break;
 
@@ -1766,6 +1770,7 @@ do { \
 			case IPV6_PORTRANGE:
 			case IPV6_RECVTCLASS:
 			case IPV6_AUTOFLOWLABEL:
+			case IPV6_RECVDSTPORT:
 				switch (optname) {
 
 				case IPV6_RECVHOPOPTS:
@@ -1827,6 +1832,10 @@ do { \
 				case IPV6_AUTOFLOWLABEL:
 					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
 					break;
+
+				case IPV6_RECVDSTPORT:
+					optval = OPTBIT(IN6P_RECVDSTPORT);
+					break;
 				}
 				if (error)
 					break;